However, Volvo isn't using the tech just to improve performance; it is using the tech to improve fuel efficiency. According to the automaker, KERS can reduce fuel consumption as much as 25 percent. In addition to improving fuel economy, Volvo says that the KERS tech can also reduce production costs compared to traditional hybrid systems.

Prototype Volvo S60 with Flybrid KERS system

Volvo has test fitted what it calls a “Flybrid” KERS to the rear axle of a S60 to assist the gas engine that drives the front wheels of the car. It captures kinetic energy typically lost from braking and sends it to the flyweel. 150 watt hours of energy can be captured in only 8 seconds, and the energy can be stored for up to 30 minutes or used immediately.

The KERS system – which spins its flywheel at a maximum of 60,000 rpm in a true vacuum and can deliver 80hp -- can be used to knock 1.5 seconds off the car's 0-60 time or in an economy mode to reduce pollution.

The entire system only weighs about 130 pounds, which makes it much lighter than a traditional electric motor and NiMH/Li-ion battery packs used in hybrid vehicles. For example, the batteries alone used in Volvo's current hybrids weigh 660 pounds.

Flybrid KERS (Kinetic Recovery System)

The prototype KERS systems won’t reach production in its current form. A production version of the system will see a similar flywheel and transmission attached to a front wheel drive-based transmission.